Method and apparatus for transporting plastics in a melted state

Abstract

A method and apparatus is provided to transport parisons from the extrusion die to a second location. The parison is extruded and a collar means is provided to contact the parison near its upper end and create a holding geometry whereby the parison is retained by the collar means without pinching the parison. The parison is then transported vertically or horizontally to the mold unit without closing or pinching the parison. The holding geometry is created by slightly deforming the parison wall near the collar means. The parison is therefore transported to the second location, for example a mold unit, instead of moving the mold unit, to the parison.

I claim:  
     
       1. A method of transporting a parison having a finite length, an upper end and an outside wall from an extrusion die to a second location during manufacture of blow-molded products, the method comprising the steps of: 
       a) vertically extruding the parison from the die;  
       b) providing two collar means each comprising two hinged pinching arms having inner faces that define a non-circular geometry;  
       c) contacting the inner faces of the collar means with the upper end of the parison to create a holding geometry between the collar means and the parison, wherein the outside wall of the parison conforms to the shape of the inner faces of the collar;  
       d) deforming the upper end of the parison to conform to the non-circular geometry of the inner faces, whereby the parison is retained by the collar means without closing the parison anywhere over its length;  
       e) separating the parison from the die without closing the parison anywhere over its length; and  
       f) transporting the parison to the second location by moving the collar means without closing the parison anywhere over its length.  
     
     
       2. The method of claim  1 , wherein the parison is cylindrical in shape. 
     
     
       3. The method of claim  1 , wherein the inner faces define a square geometry when the collar means are in contact with the upper end of the parison. 
     
     
       4. A method of transporting a parison having finite length an upper end and an outside wall from an extrusion die to a second location during manufacture of a blow-molded product, the method comprising the steps of: 
       a) vertically extruding the parison from the die;  
       b) providing two collar means each comprising two hinged pinching arms having inner faces that define a non-circular geometry;  
       c) contacting the inner faces of the collar means with the upper end of the parison to create a holding geometry between the collar means and the parison, wherein the outside wall of the parison conforms to the shape of the inner faces of the collar;  
       d) deforming the upper end of the parison to conform to the non-circular geometry of the inner faces whereby the parison is retained by the collar means without closing the parison anywhere over its length;  
       e) separating the parison from the die without closing the parison anywhere over its length;  
       f) transporting the parison to the second location by moving the collar means without closing the parison anywhere over its length; and  
       g) closing the upper end of the parison when the parison is in the second location by bringing the collar means closer together thereby straightening the pinching arms.  
     
     
       5. The method of claim  4 , wherein the parison is cylindrical in shape. 
     
     
       6. The method of claim  4 , wherein inner face define a square geometry when the collar means are in contact with the upper end of the parison.